The Electromigration of Al(Cu)/Ni Redistribution Layer in Through Silicon Via

• Main Authors: Chun-yang Tsai, 蔡鈞揚
• Other Authors: Albert T. Wu
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/46648414053790936465

碩士 === 國立中央大學 === 化學工程與材料工程研究所 === 98 === For the demands of “slim and light” electronic devices, 3D-IC technique is the most important technique, and Through Silicon Via(TSV) is an important role in this technique. However, the information of reliability is rare. In this thesis, hybrid Al(Cu)-Ni conducting lines were tested at 100oC~350oC with various current densities. The results were in comparison with thermal annealed samples. In our results, the phenomena were the same in all the TSV segments. The resistances of 100oC and 150oC samples increased about 3% after current stressing. The resistance of 200oC sample increased about 11%. There were hillocks formed at anode and voids formed at cathode in each segment. The 350oC sample did not pass the test with the current density of 5x105 A/cm2. Al2Cu was the only type of compounds formed in the standard experimental conditions, and the Al-Ni compounds only formed in extreme testing conditions. The distribution of Al2Cu is different between samples with or without current. Large compounds formed at each anode side of the samples with current and fine compounds formed at each cathode side. The effective diffusion coefficient was calculated to be about 10-13~10-14 cm2/s at conditions of 100oC~200oC. Simulations were employed in this experiment to analyze the distribution of current densities at corners of bottom TSVs when compounds were formed. Al2Cu was found to disperse the current from Al lines to the Ni lines effectively and dramatically reduced the maximum current density about 40%. These observations would be helpful for manufacturer of interconnects with TSV process in the future.